title: Intraobserver and interobserver agreement of computer software-assisted optic nerve head photoplanimetry.
abstract: OBJECTIVE
  To report the reproducibility profile of optic nerve head parameters obtained by computer software-assisted fundus photoplanimetry.
  
  
  METHODS
  Fundus photographs obtained during a population-based health survey (Sakurae Study) were planimetrically analyzed using newly developed computer software, CDSketch. The parameters assessed included vertical and horizontal cup-to-disc (C/D) ratios, superior and inferior rim-to-disc (R/D) ratios, disc and cup vertical-to-horizontal (V/H) ratios, and disc-macular distance-to-disc diameter (DM/DD) ratio. For intraobserver and interobserver agreement assessments, we calculated the coefficients of variation (CVs) and intraclass correlation coefficients (ICCs) of the mean of three measurements obtained by one observer and a one-time measurement by three observers, respectively.
  
  
  RESULTS
  The intraobserver CVs were between 2.4 % (DM/DD ratio) and 11.0 % (inferior R/D ratio), and the ICCs were between 0.868 (cup V/H ratio) and 0.976 (DM/DD ratio); all intraobserver ICCs had almost perfect agreement (>0.81). The interobserver CVs were between 2.6 % (disc V/H ratio) and 18.0 % (inferior R/D ratio), and the ICCs were between 0.762 (cup V/H ratio) and 0.930 (DM/DD ratio); the interobserver ICCs were categorized as substantial (0.61-0.80) for the inferior R/D and cup V/H ratios and as almost perfect for the other five parameters.
  
  
  CONCLUSIONS
  The consistent profiles of the planimetric parameters suggest the suitability of software-assisted photoplanimetry for assessing optic disc characteristics in glaucoma clinical study and practice.
authors.affiliation: Department of Ophthalmology, Shimane University Faculty of Medicine, Enya 89-1, Izumo, Shimane, 693-8501, Japan, tanito-oph@umin.ac.jp.
authors.forename: Masaki
authors.initials: M
authors.lastname: Tanito
authors.forename: Takeshi
authors.initials: T
authors.lastname: Sagara
authors.forename: Michiya
authors.initials: M
authors.lastname: Takamatsu
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Kiuchi
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Nakagawa
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Fujita
authors.forename: Akihiro
authors.initials: A
authors.lastname: Ohira
mesh_terms: D003941:Diagnostic Techniques, Ophthalmological; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D015588:Observer Variation; D009898:Optic Disk / Q000033:anatomy & histology*; D015203:Reproducibility of Results